#include<stdio.h>

long long int cycle1(long long int x) 
{
	long long int sum = 1;
	for (long long int i = x; i > 1; --i) 
    {
		sum *= i;
	}
	return sum;
}

void cycle2() {
	long long int sum = 0;
	for (long long int i = 1; i <= 100; ++i) 
    {
		sum +=  cycle1(i);
	}
	printf("%d", sum);
	
}

int main() 
{
	cycle2();
	return 0;
}